Page:Walker (1888) The Severn Tunnel.djvu/200

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
FALLING IN OF THE ROOF.
123

Progress of the work—1883. were bored through the door with augers, and a piece 12 inches across was broken out. Through this a considerable quantity of soft material was forced by the pressure of the water behind, and now and then large rocks were brought down which stopped the hole. For more than two months the men continued to work, taking away material which was forced through the door by the pressure of the water behind, having continually to break up with long bars and ‘jumpers’ the lumps of rock which blocked the hole. At last it became evident that it would be an endless matter to attempt to work in this manner, so the bottom heading was pushed forward until it passed well beyond the point where this door was built.

A hole was then broken up from the bottom into the top heading, and all the water from behind the door allowed to pass that way.

Men then got up into the upper heading, and found that a length of 50 or 60 feet of the roof had fallen in, and that there was an enormous cavity above, but that little water was coming from that direction.

To obtain better access to the upper heading than was afforded by the hole broken up from the bottom heading, we then drove a small side heading round the end of the head-wall, and thus had double access to the heading beyond.

We commenced at once to pole and secure a heading through the mass of débris that had fallen from the roof. We also drove a rising heading from